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Law enforcement agencies across the United Kingdom successfully lobbied to deploy a facial recognition system known to be discriminatory against women, youths, and members of minority ethnic backgrounds, after complaining that a less biased version generated a reduced number of investigative leads.

How the System Works

UK forces utilize the national police database to carry out searches using historical face recognition. This process entails comparing a “probe image” of a person of interest against a repository of over 19 million mugshots to find possible hits.

Admitted Bias

The Home Office conceded last week that the system was biased. This admission followed a study by the government's National Physical Laboratory determined it incorrectly matched Black and Asian people and women at significantly higher rates than Caucasian males. The Home Office stated it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes useful if users tolerate discrimination in ethnicity and sex. Operational ease is a weak argument for overriding basic freedoms.”

Long-Standing Problem

Official papers reveal that this bias has been known about for more than a year. Furthermore, police forces argued to overturn an earlier ruling that was intended to mitigate the problem.

Senior officers were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned NPL review found the system was had a higher probability to produce false positives for photos of women, Black people, and those aged 40 and under.

A Reversed Decision

In response, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a level where the disparity was greatly diminished.

However, this directive was overturned the next month after forces complained that the modified technology was generating a lower number of “useful lines of inquiry”. NPCC documents show the stricter setting reduced the proportion of searches that yielded potential matches from 56% to a mere under 15%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is now in operation, the latest NPL study found the system could produce incorrect matches for Black women nearly a hundred times more frequently than for white women at certain settings.

The ministry commented on these findings: “The testing found that in a limited set of circumstances the software is has a greater tendency to wrongly flag some population segments in its search results.”

Balancing Utility and Fairness

Outlining the impact of the brief increase to the system's confidence threshold, the NPCC documents state: “The change greatly lessens the impact of discrimination across legally safeguarded attributes of race, age and sex but had a significant negative impact on operational effectiveness”. The documents add that police units complained that “a previously useful tool returned results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a ten-week public review on its plans to expand the use of facial recognition technology. The minister for police the relevant minister has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, said: “There was very little discussion in race action plan meetings of the facial recognition rollout even with clear relevance with the strategy's goals.

“These revelations show yet again that the anti-racism commitments policing has undertaken through the equality initiative are failing to be integrated into broader operations. Our reports have cautioned that new technologies are being implemented in a context where racial disparities, inadequate oversight and poor data collection continue to exist.

“Any use of this technology must meet rigorous official guidelines, be subject to external review, and prove it reduces rather than exacerbates racial disparity.”

Home Office Response

A government representative stated: “We treat the findings of the report seriously and we have already taken action. A updated software has been independently tested and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be undergo evaluation.

“Our priority is ensuring public safety. This revolutionary tool will support officers to apprehend and prosecute offenders. There is human involvement in each stage of the process and no arrest or charge would be taken without specialist personnel carefully reviewing the output.”